將字典的內容寫入文件時出現分段錯誤

Question

我正在處理的代碼讀取45430個字的字典，然後將每個字中包含的字典中的所有其他字打印到文件中。我只是將獲取文件MyDictionary txt文件讀入字符數組字[45430] [30]，然後將其打印到單詞txt文件中。當我這樣做時，我在44946字處遇到seg故障，但是在同一循環中，我也正在打印到控制檯，並且所有單詞都能正確打印出來。爲什麼我在寫這個文件時遇到這個seg錯誤？爲什麼沒有seg錯誤寫入控制檯？

代碼：

#include <stdio.h> 
#include <stdlib.h> 
#include <wchar.h> 
#include <string.h> 
//char ***alloc_array(int,int); 

int main(void){ 
     FILE *fr; //declare file read file pointer 
     FILE *fp; //declare file printed file pointer 

     //char array to read in up to 30 chars 
     char line[31]; 

     long numwords=45430; //number of words in dictionary 
     int maxlength=31; // the longest string in dictionary (30 chars) 
     long i; //counts up to 45430 

     //allocate space for 45430 words at a max length of 30 chars (1 extra char for "\0")  
     char ***word = calloc(numwords, sizeof(char **)); 
     for(i = 0; i != numwords; i++) { 
      word[i] = calloc(maxlength, sizeof(char *)); 
     } 

     //Open MyDictionary.txt and determine if there is an error or not   
     fr = fopen ("MyDictionary.txt", "r"); // open the file for reading  

     if(fr==NULL){ 
       printf("\nError! opening input file"); 
       exit(1); //Program exits if file pointer returns NULL. 
     } 

     //Open words-within-words.txt and determine if there is an error or not   
     fp = fopen ("words-within-words.txt", "w"); // open the file for reading  
     if(fp==NULL){ 
       printf("\nError! opening output file"); 
       exit(1); //Program exits if file pointer returns NULL. 
     } 

     int j=0; //counts to 30 for max length 
     i=0; 
     while(fgets(line, 40, fr) != NULL){ //get a line, up to 40 chars from fr and put first . done if NULL 

      for(j=0;j<30;){ 
       word[i][j]=&line[j]; 
       j++; 
      } 
      j=0; 
      printf("\n%s",word[i][j]); //print out each word of dictionary to console on its own line 
      /* 
      if((i>4 && i<8)||(i>45428)){ 
       fprintf(fp,"\nanalyze:word[i][0]=%s\tword[i][2]=%s\ti=%li",word[i][0],word[i][2],i+1); 
      } 
      */ 
      fprintf(fp,"%s",word[i][j]); //print out each word of dictionary to words-in-words on its own line 
      i++; 
     } 
     fclose(fr); //close the files prior to exiting 
     fclose(fp); 
     return 0; 
} //main 

Answer 1

char ***word = calloc(numwords, sizeof(char **)); 
for(i = 0; i != numwords; i++) { 
    word[i] = calloc(maxlength, sizeof(char *)); 
} 

你已經有了一個間接層次太多。您正在存儲單詞列表。一個單詞是char *，所以單詞列表將是char **。

char **word = calloc(numwords, sizeof(char *)); 
for (i = 0; i != numwords; i++) { 
    word[i] = calloc(maxlength, sizeof(char)); 
} 

這將需要更改其餘的代碼。你完全可以擺脫j。這：

for(j=0;j<30;){ 
    word[i][j]=&line[j]; 
    j++; 
} 

變爲：

strcpy(word[i], line); 

而且這樣的：

j=0; 
printf("\n%s",word[i][j]); 
fprintf(fp,"%s",word[i][j]); 
i++; 

變爲：

​​

Answer 2

'字' 應該是一個指針數組，所以正確的類型是char **，而不是char ***。 陣列中的每個條目是一個指向字符的緩衝液：

char **word = (char **)calloc(numwords, sizeof(char *)); 
if (!word) 
    // exit with error 

for (i = 0; i != numwords; i++) { 
    word[i] = (char *)calloc(maxlength, sizeof(char)); // just allocate 31 bytes 
    if (!word[i]) 
     // exit with error 
} 

然後從文件的讀可以這樣來完成：

for (i = 0; fgets(line, 40, fr); i++) { 
    strncpy(word[i], line, maxlength); 
    printf("word %d: %s\n", i, word[i]); 
} 

Answer 3

爲了對存儲器中的一個塊都分配這樣：

#include <stdio.h> 
#include <stdlib.h> 

int main(void) 
{ 
    int result = EXIT_SUCCESS; 

    size_t n = 45430; 
    size_t l = 30; 

    char (* words)[n][l + 1] = calloc(n, l + 1); 
    if (NULL == words) 
    { 
    result = EXIT_FAILURE; 
    perror("calloc() failed"); 
    goto lblExit; 
    } 

    for (size_t i = 0; i < n; ++i) 
    { 
    strncpy((*words)[i], "test", l); 
    } 

    for (size_t i = 0; i < n; ++i) 
    { 
    printf("%zu: '%s'\n", i, (*words)[i]); 
    } 

    free(words); 

lblExit: 

    return result; 
}